Secondary batteries have lead plates in a liquid acid electrolyte, and particularly industrial storage batteries have tall or long plates that rest on grids in the bottoms of the batteries. When these plates expand due to oxidation, they push up their lead terminals sealed in the battery covers, which either breaks the covers or loosen their connections with the covers to cause leakage of corrosive vapors from the batteries. It is important to maintain the seal between the terminals of these secondary batteries and their housings.
Connections which permit relative movement between the lead terminals of secondary batteries and their plastic covers and/or casings are known. These connections which permit expansion of the positive battery plates due to oxidation previously comprised sliding friction seals around the terminals that often leaked due to the corrosive vapors from the battery.
Bellows boots to prevent leaks between shafts and their housing which permit relative movement between the shafts and their housings are also known. Furthermore, the molding of rigid plastic into grooves around terminals is also known.
However, there is no known plastic bellows which is molded into grooves around a movable rod-like member, not to mention for sealing a terminal of a secondary battery to prevent leakage around it.